My 1994 VW Jetta has about 96,000 miles on it and I was wondering if
it would be ok to bring it in for it's 100,000 service now, rather
then waiting until it actually gets to 100,000 miles. Which brings
up a few other semi-related questions: What exactly would be done on
a Jetta during it's 100,000 mile checkup? Is there anything I should
specifically ask to have checked out/looked at? I have noticed that
there is is rust accumulating in a couple of places, four of them
actually.
At the front drivers and passengers door, not where the door
actually opens, but where the front of the door folds into the body
when the doors are opened, down on the quasi-tiny running board type
thing.
And at the rear dorrs, the same type of accumulation, again on the
running board type thing, but this time where the doors actually
open, not where they fold into the body.
I hope that makes sense.
Thanks.

I think that would be the door "sill" area. After 10 years, in a
shaded horizontal surface like that where water can accumulate and not
evaporate for a while, rust seems pretty likely.
As for the 100K service, are you taking it to someone other than the
VW folks? The dealer should have a prescribed list of tasks. Unless
you think they are going to try to scam you...

Ben, I have a '95 Jetta. Not sure what the maintenance schedule was
for the '94 but if it's anything like the '95, the maintenance mileage
markers were set every 7500 miles (I have no idea why they picked such
an odd number).
7500 mi. maintenance is really just an oil and filter change.
15000 mi. maintenance was the 7500 maint. + tire rotation, check of
the AT shift lock and brakes.
30k mi. was the 15k + battery check, pollen filter replacement,
coolant check, tranny fluid check, spare tire check, on-board diag.
review, plus a couple others.
60k is the next big one. at that maintenance they check over the
entire vehicle (usually a road test) plus replace belts.
Depending on dealer, they may or may not do all of the listed service
at those markers. Sometimes, I have to explicitly make sure they're
going to do ALL of the stuff. Sometimes, they dealer considers those
things aside from oil/filter change and tire rotation to be "recommended".
YMMV.

Thanks guys for the info. I got my Jetta used and was more then a bit
upset to find that it didn't have a glovebox.
WTF?!?
It had a passengers side airbag, but no glovebox.
Seems that 1994 was the first year that VW had passenger side
airbags, and yet those clever Germans couldn't figure out a way to
have both the airbag and the glovebox.
Boggles the mind.
But in addition to not having a glovebox, my car came sans owners
manual and while there is a VW dealership in the area that I go to
for service, the dealership is also a Chevy/pontiac/GMC and they seem
to look at VW as some bothersome child they have to put up with.
Anyhoo, thanks to all for the info and advice, it's most appreciated.

No problem. The missing glovebox is also on the 95. I think they got
a LOT of complaints about it then (that seems to be about the year the
VW Jettas started appearing everywhere) and the '96 has a glovebox.
The other complaint I had about the '95 was the "cup holders" in the
center console. They can hold, at most, an item the circumference of
a soda can and definitely not much taller than that, too.

It senses transient vibrations in the engine cylinder case (from any
cylinder), caused by overadvanced spark timing. Its piezoelectric
transducer sends an electrical impulse to the Electronic Control
Unit, which responds by retarding the timing. It's located on the top
left side of the engine block.

No concerns, then. The car is 12 years and 133K old, after all. It
has behaved this way for at least half its lifetime. I also avoid
most pinging by selective AC operation, and switching to premium
grades in midsummer.

There's a perceptible difference between performance of all gasoline
grades; enough to make it worth my while to switch all the way to
premium. Summers are rarely hot enough here for more than a few
weeks' transition, and it doesn't exactly break the bank.

I've never assessed the difference in fuel economy. Is the increase
in mileage universal? Would I experience it between vehicles and
differing driving conditions? Your hint suggests the benefits of a
permanent switch to go far beyond the prevention of engine knock.

Out here in Iowa, midgrade is ethanol blend, and it costs two cents
less per gallon than regular (it used to cost the same). I've been
buying ethanol blend gas for years and years... never had a problem
with it.

That far from the fuel source...who'da thunk it?
Theoretically, enough free energy exists in the form of sarcasm and
road rage to power our current fleet of automobiles indefinitely. We
could eliminate dependence on foreign crude once and for all...then
we'll be hearing some serious wisecracks over subsidies ;-)